How To Build An Outdoor Fireplace Out Of Cinder Block

How to Build an Outdoor Fireplace Out of Cinder Block

An outdoor fireplace offers a cozy gathering spot for family and friends, enhancing your backyard experience. Cinder blocks, an affordable and versatile building material, are a great choice for constructing a sturdy and attractive outdoor fireplace. This article will guide you through the process of building a cinder block fireplace, outlining the necessary steps and materials.

Planning and Design

Before embarking on the construction, careful planning is crucial. Determine the desired size and shape of the fireplace, considering the available space and the intended use. A rectangular design is a classic and practical choice, but you can also explore curved or circular shapes for a more modern aesthetic. Consider incorporating features like a cooking surface, a raised hearth, or a built-in seating area.

Obtain the necessary permits from your local building department. This ensures compliance with local codes and regulations, including fire safety requirements.

Materials and Tools

Gather the following materials and tools:

Cinder blocks: Choose high-quality blocks with a solid structure. The quantity will vary depending on the size of your fireplace.
Mortar mix: Use a high-heat mortar specifically designed for outdoor applications. It provides strength and resistance to the elements.
Firebrick: For lining the firebox, choose firebricks that can withstand high temperatures. These bricks are essential for preventing heat damage to the surrounding structure.
Fireplace grate: This metal grate supports the firewood and helps with airflow.
Sand: Used to create a smooth surface for the mortar.
Water: Necessary for mixing the mortar.
Level: Ensure the structure is level and stable.
Trowel: Used to apply mortar to the blocks.
Mason's hammer: For tapping blocks into place.
Measuring tape: To accurately measure the dimensions.
Protective gear: Include safety glasses, gloves, and a dust mask.

Construction Steps

Follow these steps for building your cinder block fireplace:

1. Foundation

A solid foundation is essential for supporting the weight of the fireplace. Dig a hole that is slightly larger than the base of the fireplace. Pour a layer of gravel 4-6 inches deep and compact it thoroughly. Pour concrete into the hole to create a level foundation. Allow the concrete to cure completely before proceeding.

2. Laying the Cinder Blocks

Begin constructing the fireplace by laying the first layer of cinder blocks. Apply mortar to the bottom of each block and carefully place them on the foundation. Use a level to ensure each layer is perfectly level. To prevent the blocks from shifting, allow the mortar to set for a few hours before continuing construction.

3. Building the Firebox

Construct the firebox using firebricks. Apply mortar to the firebricks and carefully lay them to form the walls of the firebox. Leave a gap at the bottom for the fireplace grate and create a vent at the top for smoke to escape.

4. Building the Chimney

Construct the chimney using cinder blocks and mortar. The chimney should be tall enough to allow smoke to rise and escape. Ensure that the chimney is properly vented for optimal airflow and safety.

5. Finishing Touches

After completing the basic structure, apply a layer of mortar to the exterior of the fireplace. Smooth out the mortar using a trowel, creating a clean and finished look. You can also apply a sealant to protect the fireplace from the elements.

Consider adding decorative features like stone veneer or stucco to enhance the fireplace's appearance. Building a hearth in front of the fireplace provides a safe and comfortable area for gathering around the fire.

Safety Considerations

When constructing a fireplace, safety is paramount. Avoid using flammable materials near the fireplace. Keep a fire extinguisher readily available. Never leave a fire unattended and follow all safety guidelines provided by the manufacturer of your fireplace.